Nitrous plumbing A1A...??..

My set up for single carb back in the 80's. 1st ran a cheater kit on the 340 car, then a Big Shot kit on the 446 car.
2 x 1/2" outlets from tank, 2 x Holley Blue pumps, 1 for N20 fuel only, 2 x 1/2" lines (in-line filters) all the way up to regs, 1 reg for N20 fuel, 1 for carb with 3/8" lines. Micro switch activated on carb@WOT on the hit, 2 x Fuel guages set up on cowl. Ran like this for 3 years with up to a 250 shot, never tipped a plug (2 steps colder from stock for N20, NGK7's), no issues at all.
Don't necessarily need 2 pumps but if spraying 175+hp you need good reliable constant N20 fuel pressure to make power. The way I looked at it was if I'm running a 150 shot and running say 10.5's I'm gonna go up to a 200>225 shot to run 9's, you can tune the 150 shot to try and improve, (leaning things out) but 5/10ths is a lot to gain unless your way too rich or too much timing etc. Having that set up enables you to spray more as most end up doing, do it once. Never ran dual carbs.